The invention relates to a linear drive device with two motors firmly arranged relative to each other, one driving a nut, the other driving a screw spindle. Such drive devices with two firmly arranged motors are known from Swiss Pat. No. 647,305. In these known drive devices the screw spindle is always arranged rotatably, but axially fixed, whereas the axial displacement movement of the nut is led to the exterior of the device. This type of construction has been chosen in order to obtain a favorable relationship between the maximum stroke and overall length.
If such a linear drive device is designed to perform fast movements with a small stroke, which can be achieved by electronic control of the motors, the mass to be moved is important. According to the invention the moving mass can be reduced by holding the motor-driven nut axially firmly, whereas the other motor drives the screw spindle by means of a non-rotatable but axially movable coupling element.
It is advantageous to use in a drive device with a small stroke a coupling element having a rigid driving part and a membrane serving as power take-off part connected therewith. By means of such a coupling element, which allows but only a small stroke, the axially moving mass is further reduced because only the membrane is deformed.